It is proposed to continue the work of the Steering Committee of the Coronary Drug Project (CDP) and of the Coronary Drug Project Aspirin (CDPA) trials on the secondary prevention of coronary heart disease in middle-aged men recovered from one or more documented myocardial infarctions (MIs). Work is to be completed in the years-long evaluation of clofibrate and nicotinic acid. Work in the aspirin trial -- initiated in 1972 -- is to be continued and expanded.